In short
- An Oxford University study of 977,282 middle-aged men and women found that people who had their tea or coffee “very hot” had around three times the risk of oesophageal cancer compared with those who drank it warm.
- The Oxford University research, published in the International Journal of Cancer, defines any drink at 65 degrees Celsius or above as “very hot” and as posing a potential risk.
- Consuming six or more hot drinks per day also raises the risk of oesophageal cancer, according to the study data.
- The researchers suggest around one or two in every 10 oesophageal cancers could be avoided if people stopped drinking very hot beverages.
- About 1% of the UK population has a lifetime risk of squamous cell oesophageal cancer, which affects a few thousand people a year.
Drinking tea or coffee at 65 degrees Celsius or above raises the risk of oesophageal cancer about threefold compared with drinks taken warm, according to an Oxford University study of 977,282 middle-aged adults published in the International Journal of Cancer. Cancer Research UK, which funded the work, says the overall risk of the disease remains low.
How many people were studied and what did the research show?
The work analysed data from 977,282 middle-aged men and women, making it the largest study to date to establish a link between very hot drinks and cancer of the food pipe, also called the gullet, the researchers say. Participants who reported having their drinks “very hot” had roughly three times the risk of oesophageal cancer than those who drank warm tea or coffee. Consuming six or more hot drinks a day also raised the risk.
Why can very hot liquid damage the food pipe?
Steaming hot liquid can damage the cell lining of the food pipe on its way down to the stomach. The Oxford University team defines any drink at 65C or above as “very hot” and as posing a potential risk. Adding milk can cool a drink slightly, but the researchers say a milky tea or coffee may still be far too hot.
How long should a hot drink be left to cool?
Tea made immediately after a kettle has fully boiled is touching boiling point, which is 100C (212F). Once poured into a cup, that lowers to around 90C or 95C. Cancer Research UK says it is difficult to put an exact time on how long a hot drink should be left to cool. “But if you’re worried, we’d suggest just waiting until it’s comfortable to drink rather than drinking it while it’s still very hot,” the charity said.
What is the risk of oesophageal cancer?
The researchers suggest around one or two in every 10 oesophageal cancers could be avoided if people stopped drinking very hot beverages. Squamous cell oesophageal cancer is rare, affecting a few thousand people a year, and about 1% of the UK population has a lifetime risk of being diagnosed with this type of cancer. Smoking is a bigger risk factor for oesophageal cancer than hot drinks.
The study was funded by Cancer Research UK, which stresses that the overall chances of developing the cancer remain low. In separate UK health news, Esther Rantzen said she is too fragile to reach the Dignitas clinic.
Fiona Osgun from Cancer Research UK stressed: “The most important ways to reduce the risk of this cancer type are not smoking and cutting down on alcohol.”
What temperatures do drinkers and coffee sellers use?
A separate study of 118 young adults who did multiple tastings of different black coffees found most only deemed the drinks to be too hot if the temperature was 70C or above. According to takeaway coffee cup manufacturer MTPak Coffee, the ideal temperature for hot coffee on the go is between 49C and 60C, and coffee can be served at over 82C if a customer requests it extra hot.
What did the lead researcher say?
Lead researcher Dr Keren Papier said research in South America, where many people drink a very hot herbal beverage called mate, had already shown a similar link between hot drinks and oesophageal cancer. “More research is now needed to identify the exact drink temperatures linked to this increased risk,” she said.
What are the symptoms of oesophageal cancer?
Symptoms of oesophageal cancer can include heartburn, indigestion or a pain in your throat or chest, along with weight loss.
Frequently asked questions
Does drinking very hot tea or coffee increase cancer risk?
Oxford University research on 977,282 middle-aged adults found that people who drank their tea or coffee “very hot” had around three times the risk of oesophageal cancer compared with warm drinkers. Cancer Research UK says the overall chance of developing this cancer is still low.
How hot is too hot for tea or coffee?
The Oxford University researchers define any drink at 65 degrees Celsius or above as “very hot” and as posing a potential risk. Tea made straight after a kettle boils is close to 100C and falls to about 90C or 95C in the cup.
How many hot drinks a day raise the risk?
The study data from 977,282 middle-aged men and women found that consuming six or more hot drinks per day also raises the risk of oesophageal cancer.
What are the symptoms of oesophageal cancer?
Symptoms can include heartburn, indigestion or pain in the throat or chest, along with weight loss.
With reporting from BBC News.
Stock image, not from the events described. Black Coffee and Tea in White Cup is Hot — epSos.de / Wikimedia Commons (CC BY 2.0)